JACKSONVILLE, Fla. -

The 21-year-old Jacksonville man arrested in the robbery and shooting death of Shelby Farah at a MetroPCS store on Saturday goes by the nickname: Killer.

James Rhodes is charged with first-degree murder in the killing of 20-year-old Farah during a robbery of a Brentwood cell phone store. Police said that after several hours of questioning late Tuesday night and early Wednesday morning, Rhodes confessed.

Veteran Jacksonville Sheriff's Office detectives say they're relieved such a dangerous man is off the streets. They say that had received some tips in the case after releasing surveillance video of the robber, but the break they needed came when Rhodes' own family tipped detectives off.

"You've got family members coming in, and they're scared of him, saying 'Hey, it's him, he did it,'" said Jacksonville Sheriff's Office Lt. Rob Schoonover. "It was the icing on the cake right there."

Detectives said after the family spoke up, officers scoured the area and found Rhodes at a bus stop off Atlantic Boulevard.

Shelby Farah Police said Farah was found dead after officers responded to a report of an armed robbery at the store on Main Street near 21st Street on Saturday evening.

"He pointed the gun at her demanded the money," Schoonover said. "She cooperated, she was doing what he asked, and once she handed him the last bit of money, he fired three rounds, killing her."

Farah's mother waited outside JSO headquarters late Tuesday night into Wednesday morning because she wanted to see the person police arrested. She said she is happy with the job police did.

"I came in, I wanted to meet with the sheriff because I wanted to thank him myself," Darlene Farah said. "The sheriff, the whole police department, all the homicide detectives. I mean, they were out there full force as if Shelby was their daughter. I mean, they did not let go. They just kept going."

Darlene Farah had vowed to camp out at police headquarters until a suspect was arrested. Now she said she can get some rest.

"I wanted to be the first face he saw when they brought him out of the car. And I wanted my face to be the last face he saw when they were taking him to the jail," she said Tuesday.

Farah said she was relieved to hear of the arrest so she could move on to the next step.

"It was like, 'OK, this was real. Now it's time. I've got to move on. Shelby would want us to move on," she said. "And hopefully everybody in the community will pick up where Shelby left off at, as far as putting into the community."

Rhodes was released from jail a couple of months ago after being convicted of aggravated assault with a deadly weapon without intent to kill. He also has other convictions of violating parole, violating probation and battery.

Darlene Farah and a number of MetroPCS workers were in court for Rhodes first-appearance Wednesday afternoon, but he waived his appearance.  He was ordered held without bond and an arraignment was set for Aug. 14.

Farah's family says with the accused killer in jail, they can finally focus on planning a funeral to honor her legacy. They said those plans will be announced later in the week.